<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title></title>
	</head>
	<style type="text/css">
		div{
			margin: auto;
			width: 100px;
			height: 100px;
			position: relative;
			background: gray;
			padding: 50px;
		}
		span{
			position: absolute;
			
			width: 50px; height: 50px;
			background: blueviolet;
		}
	</style>
	<body>
		<div>
			<span></span>
		</div>
	</body>
	<script type="text/javascript" src="js/jquery-1.8.3.js" ></script>
	<script type="text/javascript">
		document.getElementsByTagName("div")[0].onmouseenter = function(){
			console.log("划入");
		}
		document.getElementsByTagName("div")[0].onmouseleave = function(){
			console.log("划chu");
		}
	</script>
</html>
